The objective of this research is the study of rates and mechanisms of chemical reactions. By utilizing the principle of chemical relaxation; i.e., rapidly perturbing a system at equilibrium and subsequently measuring the relaxation time characterizing the reattainment of equilibrium, it has been possible to collect kinetic data in times as short as a fraction of nanosecond. The range from minutes to this lower limit has been covered in the principal investigator's laboratory by stopped-flow, temperature-jump and ultrasonic absorption. Conversion to digital data acquisition will improve the efficiency and accuracy and accuracy with which the experimental results will be recorded and treated. Application of fast reaction techniques has been made to metal complexation, redox and hydration-hydrolysis reactions. Rate constants for elementary steps in each of these categories of chemical transformation have been determined by the use of relaxation techniques. The roles of ligand structure and conformation, internal hydrogen-bonding and protonation of metal-binding sites will be investigated. Binding of metal ions to nucleotides, vitamins, polypeptides and other compounds characteristic of biological systems will be investigated. The role of chelation in metal ion transport through membranes will be examined by determining the mechanisms of binding by crown compouns, depsipeptides and related anti-biotics in methanol. Interactions between metal-containing isopolyions and ligands will also be studied. These multi-step reactions are complex; aspects of hydrolysis are also prominent in interactions of this type. Relevant protolytic and electron transfer reactions will be examined to support these studies. Continuing emphasis on fundamental rate processes has evolved into studies on reactants with increasing structural complexity. A primary objective of thisresearch is to try and comprehend the possible biological functions of these molecules.